This invention relates to engine valve trains and, more particularly, to valve trains with ball and socket-type joints.
It is known in the art relating to engine valve trains to provide actuating members, such as rocker arms and push rods or other components, having ball and socket-type joint connections. In some embodiments, more than one rocker arm and/or push rod or other actuator may be utilized in a train to actuate a single valve or multiple valves. Assembly of such valve trains can require excessive time in alignment of the components. For example, connecting a push rod between a pair of rocker arms at ball and socket joints in order to insert the ball ends into the sockets may require simultaneously depressing the valve actuating rocker against the valve spring. Also, insertion of a single push rod into a rocker arm socket may prove difficult in alignment of the components.
The present invention facilitates the assembly of valve trains with ball and socket-type joints by providing, where appropriate, assembly guides to aid in inserting and aligning an actuating member, such as a push rod, with one or more sockets on a mating actuating member or members. In an exemplary embodiment, a primary push rod engages and actuates a primary rocker arm which is connected with a secondary push rod engaging and actuating a second rocker arm that directly actuates a valve. The primary push rod has a spherical or ball end which is received in a socket of the primary rocker arm to aid alignment and insertion of the push rod with the rocker arm socket. The invention provides a conical guide surrounding the socket which slopes inwardly toward the socket and, upon assembly, guides the end of the push rod into position in the socket with a minimum of manual guidance.
The secondary push rod must be aligned with and inserted into sockets on both the primary and the secondary rocker arms. To assist this process, the invention provides guides, each having at least one guide surface which, in a preferred embodiment, comprises a partial cone surface extending out from the lower side of each of the rocker arm sockets. In assembly, the valve actuating rocker arm is rotated in a valve opening direction and the push rod is laid upon the part-conical guide surfaces. The valve actuating rocker arm is then released and returned by the valve spring to the actuating position, causing the ends of the push rod to ride up the assembly guides and slide into the sockets on the rocker arms in its operating position.
These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.